Lung Cancer Arising in Association with Middle Lobe Syndrome

Middle lobe syndrome, caused mainly by benign inflammatory diseases, such as chronic bronchitis and bronchiectasis, is manifested clinically as a chronic cough with sputum production. The prognosis associated with this syndrome is considered good in most cases which are caused by chronic inflammatory diseases. A patient who developed lung cancer in the course of long-term treatment for right middle lobe syndrome is described. A 63-year-old woman was admitted to our hospital with complaints of right iliac bone pain. She had been treated for chronic bronchitis and bronchiectasis associated with middle lobe syndrome for 16 years before admission. Work-up of a lung adenocarcinoma originating from the right middle lobe disclosed bone metastasis to the illium. Tumorigenesis in association with middle lobe syndrome has not yet been reported, but this first reported case suggests the need to be alert to the possibility. Middle lobe syndrome was first defined, by Graham and colleagues, as middle lobe atelectasis resulting from bronchial compression by mediatinal lymph node enlargement caused by respiratory infectious diseases (1). Since the twelve cases reported by Graham et al., many other investigators have reported cases as a result of the change in definition of the syndrome suggested by Graham. Middle lobe syndrome can be categorized into one of two types: one obstructive and the other non-obstructive (2). In the obstructive type lung cancer is among the major causes, while in the non-obstructive type inflammatory diseases, such as chronic bronchitis or bronchiectasis, predominate. The prognosis of non-obstructive middle lobe syndrome is generally good (3), and tumorigenesis in this type of middle lobe syndrome has not been reported. Here, the first occurrence of lung cancer in association with right middle lobe syndrome, previously treated as chronic bronchitis and bronchiectasis for 16 years, is reported. Case Report A 63-year-old woman was admitted to our hospital because of right buttock pain. A radiograph of the right ilium showed osteosclerotic changes, while a bone scintigram showed abnormally high uptake. A bone biopsy was performed and pathological examination of a specimen from the lesion showed metastatic adenocarcinoma. The patient had been treated with various expectorants for chronic bronchitis and bronchiectasis over a period of 16 years. The chest radiograph showed collapse of the right middle lobe at her first hospital evaluation. During the 16-year course, no significant change from that initial chest radiograph had been evident (Figure 1A to D). Fiberoptic bronchoscopy at the first evaluation disclosed edema of the right middle lobe bronchus. Neither bronchial fluid after saline lavage nor brushings from the right middle lobe bronchus contained cytologically evident malignant cells. The patient was thus diagnosed with non-obstructive middle lobe syndrome. Since no significant change from the initial findings was evident in the chest radiographs obtained over 16 years, investigations of the source of the bone metastasis by abdominal computed tomography, as well as fiberoptic endoscopy of the upper and lower gastrointestinal tract, were carried out. As none of these investigations disclosed a malignant tumor, fiberoptic bronchoscopy was performed. Small bronchial polyps were found at the carina and in the right main bronchus. No obvious tumor or obstruction was found in the accessible portion of the right middle lobe bronchus (Figure 2), but cytological examination of bronchial lavage from the right middle lobe bronchus showed adenocarcinoma. Histologically, the bronchial polyps proved to be endobronchial metastatic adenocarcinoma.